Rooting Galaxy S2 - Dummies Guide

This is a step-by-step guide for absolute beginners. Please read posts #1, #2 and #3carefully and thoroughly as they will take you through the rooting procedure and answer your queries. Particularly post #3 as this has, "Tips for using this Dummies Guide".

This guide is for rooting the Samsung Galaxy S2, GT-i9100, GT-i9100M, GT-i9100T & GT-i9100P only and no other variant.***

If you are unsure of the model of your phone, go to Settings > About phone > Model number

(*** The Dummies Guide can also be used to root the, "GT-i9100G", on Gingerbread, (only), providing you use the root kernels mentioned in post #2, here)

#1.1. What is rooting?

Rooting gives you, "Superuser", access to your phone and its features. It allows the installation of the latest custom ROM's, kernels, modems, applications and features that are not available to un-rooted phones. All this process does is to replace the stock kernel, that comes with your phone, with a root kernel and does not affect any data stored on the phone. For more information on the advantages of rooting, see here.

#1.2. Is it difficult

That really depends on your ability to read and follow instructions. I would strongly suggest that you read all the links published here, carefully and thoroughly, to help you understand the process before attempting to root your phone. The actual, "flashing", process, post #2, takes about 30 seconds, however, the set-up for this is longer and can be done in advance.

With, currently, over 150,000 views and over 600 posts, we have not lost a man, (or woman), yet!

#1.3. What hardware do I need?

Galaxy S2 GT-i9100/G/M/P/T phone

USB lead that came with the phone.

A Windows PC running, XP, Vista or Windows 7

USB Jig. Although not needed to root your phone some people find it a useful tool for getting rid of the yellow warning triangle at boot-up, (personally I do not bother and it may not work on newer bootloaders), and for resetting your flash counter to potentially avoid voiding your phone's warranty if you flash back to your original firmware in case you need to take it to a service centre. See here.

When you have downloaded and installed Kies, connect your phone via the USB lead to ensure that it is working. If you encounter any problems connecting your phone to Kies, see this trouble shooting guide, here.

#1.5. The Root Kernel

Kernel. Your choice of Root kernel depends on the Android Version you are running.

Settings > About phone > Android version to determine which firmware you have.

Now, depending on your firmware version, you can download one of the following 3 kernels to root your phone.

(all the following kernels have the, "brick bug", fix where needed)

#1.6. Android Version 2.3.?, Gingerbread

This relies on matching the current kernel you have installed to a CF-Root kernel. To determine your current kernel...

Settings > About phone > Kernel version (make a note of this in case of problems)

Once you have ascertained which kernel version you are currently running you will need to go here.

For instance, if you are currently using 2.6.35.7-I9100JPKJ2-CL655700root@DELL143 #2 use CF-Root-SGS2_XW_XEF_ KJ2 -v5.0-CWM5.zip. If there is not a kernel which matches the letters and numbers in bold just go one number up from yours.

Extraction for .zip kernel files only.

Download the .zip file to your desktop and unzip it, (To extract the file, just right click on it and select 7-Zip/WinRAR/Winzip and, "Extract here". This extracted file is the one you will need.). This is the .tar file that contains the kernel that will root your phone. To avoid confusion you can now delete the original .zip file that it came with.

Put your phone into Download mode by turning it off completely and then press and hold the following buttons... Volume Down + Home (centre hard key) + (lastly) Power. Continue to hold these buttons until your phone boots into the Warning! screen asking you to press volume up if you want to continue or volume down to cancel. Press Volume Up. See video, here.

#2.2. Step 2.

Right click on Odin and select, "Run as Administrator", to open it. Ensure that the Samsung Kies programme is not running at the same time as this can cause problems

With Odin displayed on your PC screen, click on the PDA button, (a.k.a. AP on later versions of Odin), and navigate to the .tar file, that you placed on your home screen, and select it.

Make sure that Re-Partition is unchecked and that Auto Reboot, F.Reset Time and PDA are checked and that the PDA box, (a.k.a. AP on later versions of Odin), now contains your .tar file.

#2.3. Step 3.

Connect your phone, still in Download mode, to the PC using the USB lead. If you have successfully connected to Odin you should see the ID:COM box in Odin turn yellow or light blue, (depending on which version of Odin you are using).

#2.4. Step 4.

In Odin click the Start button and you should see a green progress bar above ID:COM and shortly after that the box above it will turn green with the word PASS! in it and your phone will automatically reboot.

#2.5. Should you encounter any problems with booting automatically at this stage, put your phone into Recovery mode by turning it off completely and then press and hold the following buttons... Volume Up + Home (centre hard key) + (lastly) Power. Continue to hold these buttons until your phone boots into the Recovery screen. See video. Then select, "wipe cache partition", and under, "Advanced", "wipe dalvik cache", and then, "Go back", and select, "reboot system now". Your phone should now boot up.

Congratulations! You have just rooted your Samsung Galaxy S2.

You can now disconnect from the USB lead and check your App drawer where you will find 2 extra app's have been added. These are...

CWM

Superuser

If you are unsure whether your phone is now rooted you can install Root Checker Basic, free from the Market, and run it.

***I now strongly urge you, for your own protection, to make the following backup's in case of future problems... A Titanium Backup. A Nandroid backup. An "efs", file backup. See items, ***, below for details.

#2.6. Removing the Yellow Warning Triangle at Boot-up

Because you have now installed CF-Root kernel you will notice a yellow warning triangle appear briefly when booting up your phone. Personally, this does not bother me and experienced modders tend to treat this as a badge of honour that declares their phone is rooted and capable of more than the stock version.

However, if you wish to remove the yellow triangle you can do so by either purchasing the Jig mentioned in the first post, (this may not work on newer bootloaders, see, here), or by following the instructions here.

If you are running Ice Cream Sandwich or Jelly Bean, Android 4., firmware, you can download, "Triangle Away" from the Play Store to remove the Yellow Warning Triangle.

#2.7. I'm rooted... now what?

Now that you are rooted you can start thinking about installing custom ROM's, kernels and modems as well as, "freezing", some of the, "bloatware" that comes with your phone.

Recovery and Download Modes. Here are two videos, mentioned previously, showing how to get into Recovery Mode and Download Mode. These are two states that modders constantly refer to and it will pay you to familiarise yourself with their operation.

*** (I strongly advise installing this app after rooting and using it to navigate to the, "/efs", file in the root directory of the phone and making a copy of this and putting it on both your external SD card and PC as its loss or corruption in future could render your phone unusable and require a Samsung repair) Also, free from the Play Store, is GSII Repair, which will backup/restore your efs folder.

Rooting your phone could, in theory, void your warranty. See under USB Jig in first post. Also, you will no longer be able to update your phone via Kies or OTA, (Over The Air), and will need to flash ROM's via Odin or CWM Recovery... which is probably why you rooted anyway!

Whilst I have taken every care in compiling this guide, I cannot be held responsible for any damage that may occur through its use and the decision to use this guide lies with you, the owner.

Thanks

My thanks go to the following for their help and contributions to this guide:-

I have tried to keep this, "Dummies Guide", as simple and easy to understand as possible for absolute beginners, with no prior knowledge of Android and the Samsung Galaxy S2, whilst trying to cover the most commonly asked questions about rooting.

#3.1. Please take the time to read posts #1 and #2carefully and thoroughly before posting a question as they should contain most of the answers you require.

#3.2. If my reply to a question states, "See, #1.7". It means that the answer to your query is already contained in post #1, item #7. Re-read that item again, carefully, and it should answer your question and saves me the time and trouble of having to repeat myself all over again.

#3.3. When posting a question, please include your, "Version", details as shown in post #2.0 and your, "Kernel version". as per #1.6 and if you have used another method to try and root your phone, other than the one in posts #1 and #2 of this thread, could you please post a link as this may help in discovering your problem.

#3.4. Please, please, please, help keep this thread on topic. It is designated for the actual rooting of your phone and not for general questions about kernels, ROM's, modems, etc: There are other threads on the forum for that or you can start one of your own.

#3.5. Please do not PM me with rooting questions. I will not answer them! Ask them on the forum so that others may benefit from the questions and answers.

To be honest though, it doesn't take much reading through the threads to work out the only people who have problems with rooting seem too be those who don't use chain fire. It's like chocolate fondants on master chef.......

Yes, prior to rooting as Kies only recognises stock ROM's/kernels but after rooting Kies will not update custom ROM's/kernels. After rooting there are other methods, such as CWM Manager, to do updates. Rooting is not updating...

Rooting gives you, "Superuser", access to your phone and its features. It allows the installation of the latest custom ROM's, kernels, modems, applications and features that are not available to un-rooted phones. All this process does is to replace the stock kernel, that comes with your phone, with a CF, (ChainFire), root kernel. For more information on the advantages of rooting, see here:-

That really depends on your level of competency and your ability to read and follow instructions. I would strongly suggest that you read all the links published here to help you understand the process before attempting to root your phone.

How would I go about backing up everything my phone is currently (which I currently understand to be a kernel and a ROM, and also things like modem etc? Anymore?)

I have read articles about backing up apps (use titanium backup) but cant seem to find anything specific with regard to backing up the software parts of my phone.

For example, I want to root my phone and start again from scratch, install a new kernel and ROM, have no preinstalled apps, and be able to choose my own theme/skin, and also be able to reset/roll back my phone to its original factory state/original kernel/ROM without it being noticed if I were to send it back to Samsung for repair (resetting the flash count?)

I have read a lot of articles and am fairly well versed on the basics now I believe